#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <stddef.h>
#include <unistd.h>
#include "bigfile.h"

void usage() {
    fprintf(stderr, "usage: bigfile-copy [-n Nfile] [-f newfilepath] filepath block newblock\n");
    exit(1);

}
int main(int argc, char * argv[]) {
    BigFile bf = {0};
    BigFile bfnew = {0};
    BigBlock bb = {0};
    BigBlock bbnew = {0};
    int verbose = 0;
    int ch;
    int Nfile = -1;
    size_t buffersize = 256 * 1024 * 1024;
    char * newfile = NULL;
    while(-1 != (ch = getopt(argc, argv, "n:vB:f:"))) {
        switch(ch) {
            case 'f':
                newfile = optarg;
                break;
            case 'n':
                Nfile = atoi(optarg);
                break;
            case 'B':
                sscanf(optarg, "%td", &buffersize);
                break;
            case 'v':
                verbose = 1;
                break;
            default:
                usage();
        }
    }
    if(argc - optind + 1 != 4) {
        usage();
    }
    argv += optind - 1;
    if(0 != big_file_open(&bf, argv[1])) {
        fprintf(stderr, "failed to open: %s\n", big_file_get_error_message());
        exit(1);
    }
    if(newfile == NULL) {
        newfile = argv[1];
    }
    if(0 != big_file_create(&bfnew, newfile)) {
        fprintf(stderr, "failed to open: %s\n", big_file_get_error_message());
        exit(1);
    }
    
    if(0 != big_file_open_block(&bf, &bb, argv[2])) {
        fprintf(stderr, "failed to open: %s\n", big_file_get_error_message());
        exit(1);
    }
    if(Nfile == -1 || bb.Nfile == 0) {
        Nfile = bb.Nfile;
    }
    /* avoid Nfile == 0 */
    size_t newsize[Nfile + 10];
    int i;
    for(i = 0; i < Nfile; i ++) {
        newsize[i] = (i + 1) * bb.size / Nfile
            - i * bb.size / Nfile;
    }

    if(0 != big_file_create_block(&bfnew, &bbnew, argv[3], bb.dtype, bb.nmemb, Nfile, newsize)) {
        fprintf(stderr, "failed to create temp: %s\n", big_file_get_error_message());
        exit(1);
    }

    if(bbnew.size != bb.size) {
        abort();
    }

    /* copy attrs */
    size_t nattr;
    BigAttr * attrs = big_block_list_attrs(&bb, &nattr);
    for(i = 0; i < nattr; i ++) {
        BigAttr * attr = &attrs[i];
        big_block_set_attr(&bbnew, attr->name, attr->data, attr->dtype, attr->nmemb);
    }
    
    if(bb.nmemb > 0 && bb.size > 0) {
        /* copy data */
        size_t chunksize = buffersize / (bb.nmemb * dtype_itemsize(bb.dtype));
        BigBlockPtr ptrnew;
        ptrdiff_t offset;
        BigArray array;

        for(offset = 0; offset < bb.size; ) {
            if(0 != big_block_read_simple(&bb, offset, chunksize, &array, NULL)) {
                fprintf(stderr, "failed to read original: %s\n", big_file_get_error_message());
                exit(1);
            }
            if(0 != big_block_seek(&bbnew, &ptrnew, offset)) {
                fprintf(stderr, "failed to seek new: %s\n", big_file_get_error_message());
                exit(1);
            }

            if(0 != big_block_write(&bbnew, &ptrnew, &array)) {
                fprintf(stderr, "failed to write new: %s\n", big_file_get_error_message());
                exit(1);
            }

            free(array.data);
            offset += array.dims[0];
            if(verbose) {
                fprintf(stderr, "%td / %td done (%0.4g%%)\r", offset, bb.size, (100. / bb.size) * offset);
            }
        }
    }
    if(0 != big_block_close(&bbnew)) {
        fprintf(stderr, "failed to close new: %s\n", big_file_get_error_message());
        exit(1);
    }
    big_block_close(&bb);
    big_file_close(&bf);
    big_file_close(&bfnew);
    return 0;
}